Just because you couldn't figure it out doesn't mean the capability wasn't there. More than ten years ago at this point I was running a massively scaled Celery + RabbitMQ + Redis deployment with excellent off-the-shelf reporting using Flower.

I'm going to back GP, eight years ago my team developed a system that was basically an async, scheduled, async task queue, we used celery, and it was so buggy and so troublesome that at some point we switched to a hastily hacked own solution and it worked better.

It's entirely likely that we did something wrong and misused celery. But if many people have problems with using a system correctly then it's also something worth considering.